Automatic towline release



Jul 12, 1960 s. A. BARTKOWIAK 2,944,506

AUTOMATIC TOWLINE RELEASE Filed March 5, 1958 2 Sheets-Sheet l INVENTOR BY g I ATTORNEY 2 Sheets-Sheet 2 Filed March 5, 1958 IN VENTOR ATTORNEY a flfiarikawz'als 21%;?

U ted Sta es. PatmtO 2,944,5 AUTOMATIG TOWLINE RELEASE Stanley A. Bartkowiak, 42710 Bemis Road, Belleville, Mich.

This invention relates to a device for automatically releasing a towline and has for its primary object to provide a safety device for coupling the towline of a surfboard or water skisto a towing boat and in such a manner that when the boat is under way and moving at a normal speed for towing a water skier or a surfboard rider, an increase in the pull on the towline will automatically release the towline.

Another object of the invention is'to providean automatic towline release having means to prevent O eration of the release mechanism when the-boat is moving ata reduced speed, so that the towline will not be released while a skier or surfboard rider isinitially being brought to a planing position on the surfaeepf the water and section, of a preferred form of the automatic towline release; V Figure 2 is a rear elevational view, partly'in vertical.

section and partly broken away thereof, taken substan} tially along a plane as indicated by the line 221of Figure 1; g t A Figure 3 is a fragmentary vertical sectional view, taken substantially along a plane as indicated by the line 3-,-3-

of Figure 2; w

Figure 4 is a top plan view-indetail and partly in section, taken substantially alonga plane as indicated by the line 4-4 of Figure '2;'

Figure 5 is a fragmentary side elevational view, partly in vertical section, of a slightly modified form of the automatic tow release;

Figure 6 is an enlarged fragmentary vertical sectional view thereof taken substantially along a plane as indicated by the line 6-6 of Figure 5; v

Figure 7 is a fragmentary side elevational view, partly in vertical section, of another modified form of the tow release, and l p ,Figure 8 isan enlarged fragmentary vertical sectional view, taken. substantially along a plane as indicated by the line 8--8.of' Fig'ure 7'. w v 1 v t I Referringmore specifically to the drawings, and first with reference to Figures 1 to 4, "the automatic tow v release as discl0sed'in1these .viewsjisdesignated'lgenerally 10 Qandincludes amounting plate ,111 which' isls'ecured while the boat is accelerating," during which period a considerably greater pull or drag is exertedon the towline than when the skier or surfboard rider"'is; 'planing on the surface of the water and while the boatis traveling at a normal speed.

A further object of the invention is to provide an automatic tow release adapted to releasably couple two towlines to a boat for towing two water skiers or surfboard rides and which release is operable for individually re-' leasing either towline in response to an excessive pull thereon and after acceleration of the boat.

It is, accordingly, an object of the invention to provide a safety device for protecting water skiers and surfboard ridersas well as occupants of a boat or the boat itself 7 from injury while the boat is employed for towing-water skiers or surfboard riders. When a surfboard rider falls from a surfboard, the surfboard usually ,flips over I and is caused to submerge and is pulled toward the bottom.

7 This .produces a sudden jerk on the boatwhich frequently causes the operator and passengers to be thrown from the boat and may in addition cause the transom to be torn loose from the remainder of the hull, and any of which results can cause considerable injury and damage. With the automatic towline release the additional pull would automatically release the towline so that these mishaps could not occur. Similarly, if a water skier falls and becomes entangled in and is unable to. release 7 sides 15 of the boss 14 and are provided with central apertures which align withthe opening 16 to receive a the towline the increased pull in a like manner release the towline to avoid the aforementioned mishaps or injury to the skier. crossed by another boat a sudden increased puller jerk on the towline will effect releasej thereof and thus protect the water skier or surfboard rider from injury.

A further object of the invention is to provide a tow release whereby either of two skiers can automatically release himself and his towline from the towing'boat by merely jerking suddenly onthe towline so that the boat can continue pulling the other skier and without dragging an extra towline.

In addition, should the towline be 20 whichis interposed, therebetween.

by fastenings 12 to the outer side; of the rans m 13j of'a boat, above the waterline The exposed'onrear side of the mounting plate" 11 is provided with a';large I protuberance including a lower portion forming a boss 14, having corresponding substantially parallelopposite sides 15. The boss 14 has an opening 16 extending centrally therethrough. The opposite sides 15' are fiat except for two rounded projections 17 which are equally spaced from and disposed on opposite sides of the central'opening v16 in diametrical alignment with one another. The protuberance, of which the boss 14 forms a part also includes two vertically spaced rearwardly extending plates 18 and 19 which are connected by a bracing web The vertically spaced plates 18. and 19 have two complementary rear- Iwardly opening slots or notches 21 and 22 which are laterally spaced. from, one another, as best seen in Figure 2.

Discs 23 and 24' are disposed against the opposite bolt 25 which extends through said discs and through the, opening 16 and which has a head 26 hearing against the outer sideof the disc 24. The inner face ofeach disc 23 and 24 is provided with two pairs of depressions 27 and 28. The depressions of each pair are disposed in diametrical alignment with one another and areequally' spaced from the center of the disc and arespacedapart a distance corresponding tolthe spacing between the pro: tuberan'ces 17 of each side 15. The discs 23 and 24 have rigidly connected or integral arms 29 and 30, respectively, which extend substantially tangentially'fr'om peripheral portions of said discs, as seen in Figuresl and'3q x I I "A nut and washer 31 are mounted on the opposite threaded end ofthe bolt 25, spaced from the disc 23; and a compression spring 32 is mounted 'on the bolt 25 between the disc 23 and the nut and washer 31 and under Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawings, illustrating presently preferredembodiments thereof, and wherein' .Figure his a. side elevational view, partly in ivertical" compression for urging the discs 23 and 24 against the two sides'15 of the boss 14. The discs 23 and 24 can be rotated to position the arms 29 and 30, respectively, thereof in substantially upright positions so that said arms project upwardlythrough the' vertically alignedslots: or

notches 21 and 22, respectively,jand when'the discsare" Patented July 12, 1960 k 3 thus disposed as illustrated in Figures 1 to 4, the depressions 27 of each disc will be disposed to receive the two rounded projections or latch elements 17 which project from the side against which said disc is disposed, and the spring 32 will hold said discs 23 and 24 with their inner sides flush against the boss sides 15, for thus releasably latching the discs in their positions as illustrated with the arms 29 and 30 in upright positions and extending through the slots 21 and 22, respectively. The

amount of force required for swinging either the arm 29 or the arm 30 downwardly and outwardly by rotation of the disc 23 or 24, respectively, can be varied by tightening or loosening the nut and washer 31 to vary the compression of the spring 32.

A short post 33 extends upwardly from the top plate 19 and is disposed between the inner ends of the notches 21 and 22 and the mounting plate 11. A latch plate 34 has a rear edge provided with aligned spaced barrel portions 35. The plate 34 has a notch 36 in its rear edge, as seen in Figure 4, to accommodate the post 33 and so that the barrels can be disposed with their bores in alignment with the aperture of said post 33 to receive a pivot pin 37 by means of which the plate 34 is swingably mounted on the post 33. The plate 34, adjacent its forward edge, is provided with transversely spaced pening 38 and 39 in which he upper en s o he arms 29 and 30, respectively, are disposed, when said arms are in upright positions and when the latch plate 34 is swung downwardly to a position above and substantially parallel to the upper plate 19, as illustrated.

An aperture lever arm 40 extends upwardly, and for-' wardly from one barrel 35 at an obtuse angle to the plate 34. Oneend of a pin 41 is pivotally mounted at 42 on an upstanding car 42' of the upper plate 19 and the other free end portion of said pin 41 extends loosely through the aperture of the lever arm 40. A spring 43 is mounted on the pin 41 between the ear 42' and lever arm 40 for urging said lever arm 40 to swing upwardly and rearwardly so that the plate 34 is urged to swing downwardly toward the plate 19. 1

A crank arm 44 extends upwardly and forwardly at an obtuse angle from the outer end of the other barrel 35 and has an outwardly extending crank pin 45 at its outer end to which one end of a connecting rod 46 is pivotally connected. A bracket arm 47 is secured to and extends rearwardly from a lower portion of the transom 13. A lever 48 having arms 49 and 50 is pivotally mounted by a pivot pin 51 at its apex on the outer end of the bracket arm 47. The arm 50 of said lever extends inwardly from the pivot 51 and is pivotally connected at its free end to the other end of the connecting rod 46, and the other lever arm 49 extends downwardly from the pivot 51 and is laterally enlarged to form a plate, as seen in Figure 2, which is disposed crosswise of the axis of the boat and below the level of the bottom 52 of the stern portion of the boat hull, as seen in Figures 1 and 2.

Complementary forward ends of two towlines 53 and 54 are provided with coupling rings or links 55 and 56, respectively, which links fit between the plates 18 and '19 and are engaged by the disc arms 29 and 30, respectively, which extend upwardly therethrough when the discs 23 and 24 are releasably latched in their positions as shown.

Assuming that the opposite ends of tow lines'53'and 54 are connected to surfboards or are engaged by water skiers, in a conventional manner, when the boat is initially under way or moving from left to right of Figure 1, the latch plate 34 will engage over the upper ends of the arms 29 and 30 to prevent said arms from being swung downwardly and rearwardly in counterclockwise directions for releasing the towline rings 55 and 5.6, due to the heavy pull on the towlines, whilethe surfboards or water skis are being brought into planing positions. After the boat has accelerated to a sufiicient extent to ef fect planing of the water skis or surfboards, the pressure of the water against the forward side of the plate 49 will cause the lever 48 to turn clockwise as seen in Figure 1 to exert a downward pull on the connecting rod 46 and crank 44 for swinging the plate 34 upwardly and out of engagement with the upper ends of the arms 29 and 30, to thus release the latch plate 34. The pressure of the spring 43 will determine the cruising speed of the boat which is necessary to efiect release of the latch plate 34 so that the release 10 may thereafter function automatically to release the towlines 53 and 54. The adjustment of the spring 32 determines the amount of pull required to cause either arm 29 or 30 to swing downwardly and rearwardly with its disc 23 'or 24, respectively, to effect release of the towline coupled thereto. Thus, should the pull on either towline be materially increased the arm 2? or 30 to which said towline is connected will be swung downwardly and rearwardly to allow the ring of said towline to disengage said arms to thus automatically efiect release of the towline if the surfboard connected thereto should overturn and submerge or if the skier pulled thereby should fall and become entangled in the towline. Likewise, a skier by exerting a sudden jerk on his towline can effect release thereof in the same manner and while the other skier, pulled by the other towline will, remain connected to the boat by the automatic towline release it It will also be apparent that before the boat can slow down sufficiently so that the drag on the towline is materially increased, the spring 43 will overcome the pressure on. the lever plate 49 and return the latch plate 34 to its latched position as illustrated, so that the towlines will not be automatically-released should the boat be required to slow down momentarily or while the boat is preparing to stop. It will also be apparent that any other cause producing an increased pull on either towline or a sudden jerk will automatically eficct release of said towline if the boat is traveling at a normal cruising speed suflicient to maintain the latch plate 34 in a released position, 1

Figures 5 and 6 illustrate a slightly different embodiment of the automatic towline release, designated generally 57, and wherein the lever 48 and connecting rod 46 are omitted. In lieu of the upwardly and rearwardly extending crank 44, one of the latch plate barrels 35 is provided with a downwardly and forwardly extending crank arm 58 having an outwardly extending crank pin 59 which is pivotally conencted to one end of a connecting rod 60 which extends forwardly therefrom loosely through an opening 61 of the boat transom 13'. A bracket arm 72 is secured to and projects from the inner side of the transom 13'. A bell crank 62 is pivotally mounted at its apex on the bracket arm 72 and has an upwardly extending arm 63 to which the other forward end of the connecting rod 60 is pivotally connected.

A bracket arm 47 is secured to and extends rearwardly from a; lower portion of the outer side of the transom 13 and has an arm 64 pivotally connected thereto and extending downwardly therefrom and which is provided with a bore or passage 65 which is provided with a forwardly opening lower end disposed below the level of the stern portion of the bottom of the boat hull 52. and a rearwardly opening opposite end to which is conneeted one end of a flexible conduit or tubing 66. The opposite end of the'tube 66 is connected to the rear end of a pipe 67 whichextends rearwardly through the transom 13. The other end of the pipe 67 is adapted to be connected to a boat speedometer, not shown. The

parts 64 through 67 constitute conventionalparts of a boat speedometer. operated by variations in pressure created in the pipe 67 by forward motion of the boat and whereby water is forced through the passage 65 and tube 66 into pipe '67 to create the pressure in said pipe, The member 641s mounted on a sufficiently tight pivot to 5. normally maintain its position of Figure S and is swung upwardly and rearwardly only by striking an obstruction.

A T-coupling 68 is interposed in the conduit 67 and a pipe or tube 69 connects with and extends upwardly from said T-coupling and has its opposite end connected with an opening into a cup shaped member 70 having an open upper end which is closed and sealed by 21 diaphragm 71, as best seen in Figure 6. Thecup member 70 is supported by a bracket arm 72' which is secured to the inner side of the transom 13'. One end of a rod 73 is secured to the central portion of the diaphragm 71 and the other end of said rod is pivotally connected to the free end of the other arm 74 of the bell crank 62, which is disposed above the diaphragm. V

The automatic towline release 57 is otherwise identical with the towline release and the latch plate 34' thereof is urged downwardly into alatching position by the spring 43 bearing against the lever 40'. The lever 58 is thus urged forwardly or toward the transom 13 and the bell crank 62 is held in its position of Figure 5 so that the diaphragm 71 is flexed inwardly of the cup member 70, to prevent release of the automatic tow release 57 while the boat is not under way or moving at a slow speed. As the boat reaches a normal cruising speed for pulling surfboards or water skiers, pressure is built up sufficiently in the pipes 67 and 69 and the cup member 70 to distend the diaphragm 71 upwardly and outwardly of the cup member 70. This movement exerts an upward thrust on the rod 73 which swings the bell crank 62 counterclockwise about its pivot to exert a rearward thrust on the connecting rod 60 'and lever 58 for swinging said lever, the latch plate 34' and lever 40' speed of movement of the boat diminishes to below its' normal cruising speed the pressure in the pipes 67 and 69 and in the cup 70 will be diminishedso that the spring 43" will return the latch plate 34 to its latched position of Figure 5 and will return the diaphragm'71" to its position of Figure 6.

Figures 7 and 8 illustrate another modified form of the automatic towline release, designated generally 75 and which constitutes a variation of the towline release 57. The lever arm 58' of the latch plate 34" extends upwardly rather than downwardly from the pivot 37" and one end 'of 'a connecting rod 76 has a pivoted and limited sliding 'connection with the upper end of the lever 58? andre xtends forwardly therefrom loosely through an opening61 of a'boatitransom 13"; The otherv end of the connecting rod 76 forms an armature 77 which is disposed in a solenoid 78. The solenoid 78 is supported by a bracket 79 which is secured toand projects from the inner side of the boat transom 13". The tow release 75 includes'parts 4 64',"65', 66', 67, 68', 69', 70' and 71', corresponding with the parts 47', 64, 65, 66,67, 68, 69, 70, and 71,- respectively. The cup member 70' is supported by a bracket arm 89 which is secured to the inner side of the transom 13 and which has an up wardly offset free end portion 81 which is disposed over the diaphragm 71' and which provides a guide for a plunger 82 which extends slidably therethrough. The lower end of the plunger 82 is secured to the central portion of the diaphragm 71 and a compression spring 83 is mounted on the plunger 82 between the guide 81 and the diaphragm '71 for urging the plunger rod and diaphragm downwardly relatively to the cup member 70.

An electric switch 84 is supported above the guide 81 by a standard or bracket 85, which extends upwardly clockwise about the pivot 37', of said parts for moving from the guide 81. The switch 84 has a-fixed contact 86 and a resilient contact 87,which is disposed beneath the contact 86 and isnorm'ally springbiased downwardly to an open position of the switch. A push rod 88 is a supported by and extends downwardly from the con-- tact 87 through a guide 89 which forms a part of the switch 84, and the lower end of the push rod 88 is normally disposed above and spaced from the head of a screw 90, which is threaded in the upper end of the plunger 82, as'seen in Figure 8, when the diaphragm 71 is flexed inwardly of'the'cup member 70'. p

A conductor wire 91 leads from one contact of the solenoid 78 to one side of a self-contained current source such as a storage battery 92, and a conductor wire 93 extends from the other connection of the solenoid 78 to the switch contact 87. A conventional double throw type electric switch 94 may be mounted at any suitable remote point, as for example, adjacent the controlsof the boat and includes two stationary contacts 95 and 96' latched position to prevent release of the towlines. If p the contact 97 is moved into engagement with the contact 95 a circuit will be completed between the battery and solenoid so that the pull rod 76 will be drawn forwardly to..rock1the latch plate 3d" upwardly for relasing the towline ring engagingarms so that said arms may swing to positions to release the towline rings, even though the boat is not traveling'at acruising speed. By positioning the-contacts 97 in engagement with the contact 96 a circuit will be completed to the solenoid 78 only when the switch 84' assumes a closed position. accomplished by a sufficient hydraulic pressure building up in the cup member 70 to distendthe diaphragm 71' outwardly thereof and so that the plunger 82 is displaced upwardly to eflect an upward displacement of the push rod '88 for moving the switch contact '87 into engagement with the switch contact 86. Adjustment of the screw varies the amount of pressure required in the cup member 70' to-thus efiect release of the latch plate 34", and thus varies the speed at which'the boat must be moving to move the latch plate 34" to a released position. It will be obvious that the spring 43" will returnthe latch plate 34" to a latching position when-V ever the solenoid 78 is de-energized.

Various modifications and changesin the embodiments of the invention as disclosed are contemplated and may be resorted to, withoutdeparting from the function or scope of the invention as hereinafter defined by the appended claims. r

I claim as my invention:

1. An automatic towline release comprising a base plate having a rearwardly projecting boss, a journal member extending through and supported bysaid boss, a disc journaled on said journal member, said disc and boss having normally abutting'faces, spring means carried by the journal member and urging said disc face against the This is.

plate for turning said disc against the resistance of said latch means.

2.v An automatic towline release comprising a mounting plate, a towline engaging arm, means turnably supporting said arm on one side of said mounting plate for swinging movement toward and away from the mounting plate, a boss fixed to the mounting plate and disposed adjacent a part of said arm, spring latch means including a portion interposed between the boss and said part of the arm for releasably latching said arm against swinging movement and responsive to an excessive torsional force or a sudden jerk exerted on said arm in a direction away from the plate to release the arm for swinging movement outwardly and away from the mounting plate to a released position.

3. An automatic towline release as in claim 2, spaced plates supported by said mounting plate and having notches opening away from the mounting plate in which portions of said arm are disposed in an operative position of the arm.

4. In combination with a boat including a transom and hull bottom, and a towline having an attaching loop at one end thereof; an automatic towline release comprising a mounting plate secured-to the outer or rear side of said transom and having an outer rear side facing away from the transom, a boss fixed to and extending from the outer side of said plate, a towline engaging arm, means turnabiy supporting said arm on said boss for swinging movement toward and away from the mounting plate, said arm extending through the towline loop and being disposed nearly parallel to the plane of the mounting plate, in an operative position of the arm, for connecting the towline to the towline release, spring latch means including a portion interposed betweensaid boss and a part of the arm for releasably latching said arm against swinging movement and responsive to an excessive torsional force exerted on said arm, in a direction away from the plate, to release the arm for swinging movement from the operative position thereof outwardly and away from the plate to a released position for release of the towline loop from the arm.

5. An automatic towline release as in claim 4, a latch plate pivotally supported by the mounting plate and having an opening engaging over a free end of said arm, when the arm is in an operative position and when the latch plate is in an operative position extending outwardly from the mounting plate, spring means bearing against a portion of said latch plate and urging the latch plate to swing outwardly to an operative position, and means connected to said latch plate and including a first part extending below the hull bottom and which is responsive to the pressure of the water through which the boat hull is moving for transmitting a force developed by the water pressure through said means for displacing the latch plate upwardly to a released position when a predetermined pressure is exerted against said pressure responsive means.

6.. An automatic towline release as in claim 4, a latch plate swingably supported by the mounting plate and having an opening for engaging over a free end of said arm when the latch plate is swung outwardly relative to the mounting plate to a latching position to prevent swinging movement of said arm to a released position, and means including a first part extending downwardly below the hull bottom and responsive to pressure of the water in which the boat is moving and a second part connected to said'latch plate and first part and transmitting the force exerted by the pressure of the water on said first part to the latch plate for swinging the latch plate to a released position out of engagement with said arm in response to a predetermined pressure against said first part of the pressure responsive means.

7. An automatic towline release as in claim 6, said pressure responsive means including a conduit. having a submerged forwardly opening end constituting said first part thereof, a cup shaped member connected to said conduit and having an open end closed by a diaphragm, said diaphragm being responsive to the pressure in the chamber formed by said cup shaped member and diaphragm whereby the diaphragm is distended outwardly of the cup shaped member in response to a predetermined pressure in said chamber, and link and lever means connecting said diaphragm to the latch plate for swinging.

the latch plate upwardly to a released position when the diaphragm is distended, a part of the conduit, said cup shaped member, diaphragm and link and lever means forming portions of said second part of the pressureresponsive means.

8. An automatic towline release as in claim 7, and spring means acting against said latch plate and against said pressure responsive means and urging the latch plate outwardly to a latching position.

9. An automatic tow release as in claim 8, and an electrically energized solenoid interposed in said link and lever means and operable when energized to move the latch plate to a released position, a first normally open electric switch movable to a closed position. by move ment of the diaphragm to a distended position, a second manually actuated electric switch movable to one position for completing a circuit to the solenoid through the closed first electric switch and movable to a second position for completing an electric circuit to the solenoid around the first switch.

References Cited in the file of this patent UNITED STATES PATENTS Notestein June 8, 1948 ere. an, 

